1. Field of the Invention
The present invention relates to switching power supplies, and particularly to a DC-DC voltage converter with low power loss.
2. Description of Related Art
Direct current to direct current (DC-DC) voltage converters (voltage converter for short) based on a bridge switching circuit are widely used in modern electronic devices, such as computers, mobile phones, etc. A traditional voltage converter utilizes one or more pull-up and pull-down transistors (composing a bridge switching circuit) to produce an alternating current (AC) signal. The AC signal is then applied to a low pass filter composed of an inductor and a capacitor. The low pass filter passes the DC component of the AC signal to the output of the voltage converter to power functional components of an electronic device. Detailed structures and characteristics of the traditional voltage converter are introduced by Volkan Kursun et al., “High Input Voltage Step-down DC-DC Converters for Integration in A Low Voltage CMOS Process”, IEEE Proceedings of 2004 International Symposium on Quality of Electronic Design, pp. 517-521, San Jose, Calif., USA, 22-24 Mar. 2004.
For electronic devices, to minimize energy consumption is very important, especially for portable electronic devices. An energy consumption efficiency of the voltage converter of the electronic device in a light load mode decides the standby time of the electronic device. However, the energy consumption efficiency of the voltage converter in the light load mode is high, and the standby time of the electronic device is limited.
Therefore, an improved voltage converter is needed to address the aforementioned deficiency and inadequacies.